Construction Of DC Motors

By



There are three main classifications

  • 1.       Self-excited
  • 2.       Separately excited
  • 3.       PM based

 

Construction

          The stator of the dc motor has poles, which are excited by dc current to produce magnetic fields.

          In the neutral zone, in the middle between the poles, commutating poles are placed to reduce sparking of the commutator.  The commutating poles are supplied by dc current. 

          Compensating windings are mounted on the main poles.  These short-circuited windings damp rotor oscillations.  . 

          The poles are mounted on an iron core that provides a closed magnetic circuit.

          The motor housing supports the iron core, the brushes and the bearings.

          The rotor has a ring-shaped laminated iron core with slots.

            Coils with several turns are placed in the slots.  The distance between the two legs of the coil is about 180 electric degrees.

          The coils are connected in series through the commutator segments.

           The ends of each coil are connected to a commutator segment. 

          The commutator consists of insulated copper segments mounted on an insulated tube. 

          Two brushes are pressed to the commutator to permit current flow.

           The brushes are placed in the neutral zone, where the magnetic field is close to zero, to reduce arcing.

          The rotor has a ring-shaped laminated iron core with slots. 

          The commutator consists of insulated copper segments mounted on an insulated tube. 

          Two brushes are pressed to the commutator to permit current flow.

           The brushes are placed in the neutral zone, where the magnetic field is close to zero, to reduce arcing.



Related Tutorials